AI Agents Accessible APIs
A curated, machine-readable encyclopedia of third-party APIs and MCP servers that AI agents can call on a user's behalf.
This article is about services an AI agent can operate programmatically, not AI products used by humans through a web UI.
| Type | API & MCP catalog |
|---|---|
| Entries | 330 |
| Categories | 29 |
| Official MCP servers | 230 |
| Languages | English, Polish |
| Format | JSON, Markdown, HTML, llms.txt |
| Last checked | 2026-09-24 |
| License | CC BY 4.0 (data), MIT (code) |
AI Agents Accessible APIs is an open, bilingual (English/Polish) catalog of 330 services (each with a last-checked date) in 29 categories that an autonomous AI agent — such as Claude, ChatGPT, Gemini or a custom LLM agent — can use without a human in the loop, after a one-time human step: registering an account and handing the agent an API key, an OAuth token, or a connection to an MCP (Model Context Protocol) server. Every entry records the documentation URL, the authentication method, the availability of an official or community MCP server, and the free tier. The list is not a directory of products with “AI” in their name; the criterion is agent operability, not branding.
Machine-readable access (for AI agents)
AI agents should not parse this page. Fetch one of these stable files instead:
llms.txt— short index for LLMs, links to everything belowllms-full.txt— the whole catalog as compact plain text, one line per servicecatalog/all.json— full catalog, one JSON arraycatalog/<category>.json— one file per category, for small context windowsdata/schema.json— JSON Schema of an entry
Recommended agent workflow: (1) pick the category file, (2) filter by auth and mcp.type, (3) read docs (or llms_txt / openapi when present), (4) ask the user for the credential named in auth_hint.
Inclusion criteria
- The service exposes a public, self-serve programmatic interface (REST, GraphQL, SDK) or an MCP server.
- A human needs to act at most once — sign up and create a key or approve OAuth. After that the agent works unattended.
- The interface is documented and currently active (links last checked on the date shown in the infobox).
- Consumer-only apps, waitlists, sales-gated enterprise products, agent frameworks and IDEs are excluded — they are agents or tools for building agents, not services an agent calls.
Legend
- MCP ✅ — official MCP server maintained by the vendor
- MCP ◐ — community-maintained MCP server
- MCP — — no MCP server known; use the REST API
- 🆓 — free tier or free usage without payment
- ★ (date) — proof under the service name: SourceForge rating and review count, GitHub stars, Smithery uses — linked, with the date fetched
Ratings and usage (★) fetched: .
Web search
Search engines and answer APIs that return fresh web results, snippets or full page content in agent-friendly formats. — 14 services. JSON: catalog/web-search.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Brave Search API GitHub 1,467★ brave/brave-search-mcp-server Smithery 119.0k uses SourceForge 4.5★/2 reviews | Lets an agent query Brave's independent web/image/video/news search index and get cited, LLM-ready results. | API key | ✅ | 🆓 $5 free monthly credits (~1,000 queries on Search plan); credit card required at signup as anti-fraud measure | docs |
| Exa SourceForge 5.0★/1 review | Lets an agent run neural or keyword web search, retrieve page contents, and find similar links via Exa's API. | API key | ✅ | 🆓 free tier: $10 free credits/month (~1,400 searches), no payment method required | docs |
| Jina AI Search / Reader | Search the web or convert any URL into clean LLM-ready markdown via simple HTTP GET requests. | API key | ✅ | 🆓 No key needed for Reader only: 20 RPM (Search is blocked without a key); free API key gives Reader 500 RPM / Search 100 RPM plus 10M free tokens one-time on signup | docs |
| Kagi Search API GitHub 528★ kagisearch/kagimcp | Run programmatic, ad-free premium web/news/image/video searches and extract page markdown via a paid REST API. | API key | ✅ | no free tier: pay-per-use, $12 per 1,000 search requests, invoiced monthly or at $100 usage, whichever first | docs |
| Linkup Smithery 213 uses | Lets an agent search, fetch pages, or run deep multi-source research via Linkup's Search/Fetch/Research API endpoints. | API key | ✅ | 🆓 $20 free credits/month for new accounts signing up with a professional email | docs |
| Mojeek Search API | Query Mojeek's independent web index for titles, URLs and snippets in JSON or XML, with country/language boosting. | API key | — | limited-query free trial available on request; paid plans from £2 CPM (Startup, 5 req/s, 100k/day cap) | docs |
| Parallel Web Systems Search API | Lets an agent run Parallel's low-latency Search API for web research, content extraction, and entity discovery. | API key | ✅ | 🆓 free: 5,000 requests/month across APIs, plus up to $80 signup credit and $5/month free credits | docs |
| Perplexity Sonar / Search API | Lets an agent call Perplexity's Search API or MCP tools (search/ask/research/reason) for real-time grounded web answers. | API key / OAuth | ✅ | Paid only: no confirmed free tier; pay-as-you-go, Search API billed at $5 per 1,000 requests ($1 per 1,000 for the fast search variant) | docs |
| SearchApi.io | Fetch structured JSON results from Google, Bing, YouTube, Amazon, TikTok and 50+ other search engines via one REST API. | API key | ✅ | Trial: 100 free requests one-time on signup, no credit card required; then Developer plan $40/mo for 10,000 searches | docs |
| SearXNG (self-hosted JSON API) GitHub 1,260★ ihor-sokoliuk/mcp-searxng | Query a self-hosted SearXNG metasearch instance's JSON API to aggregate results from many search engines at once. | none | ◐ | 🆓 free, no key (self-hosted; you run and pay for the instance yourself) | docs |
| SerpApi GitHub 173★ serpapi/serpapi-mcp | Lets an agent scrape structured JSON results from Google and 20+ other search engines via SerpApi's REST API. | API key | ✅ | 🆓 free plan: 250 searches/month, 50 requests/hour throughput | docs |
| Serper GitHub 169★ marcopesani/mcp-server-serper | Lets an agent fetch fast, low-cost Google search results (web, images, news, maps, shopping) via Serper's REST API. | API key | ◐ | Trial: 2,500 free queries one-time on signup, no credit card required; then prepaid query packages | docs |
| Tavily Smithery 1,575 uses | Lets an agent call Tavily's search API or MCP server to run web searches and get AI-ready summarized results. | API key | ✅ | 🆓 free tier: 1,000 API credits/month, no credit card required | docs |
| You.com API SourceForge 5.0★/1 review | Lets an agent call You.com's Search/Answer/Research API or MCP server for LLM-ready web search and grounded answers. | API key | ✅ | 🆓 Free: 100 queries/day with no API key or sign-up through the MCP free profile (search and discover only); new API-key accounts also get $100 in one-time credit | docs |
Web scraping and browser automation
Crawl, scrape and convert pages to Markdown/JSON, or drive a remote headless browser (clicks, forms, logins). — 18 services. JSON: catalog/web-scraping-browser.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Anchor Browser SourceForge 5.0★/1 review | Provision authenticated cloud browser sessions and turn any website into callable MCP tools for agents. | API key | ✅ | 🆓 $5 free credits/mo, no card required | docs |
| Apify Smithery 218 uses SourceForge 4.8★/1,714 reviews | Run web scraping/automation 'Actors' from a marketplace of thousands, and manage datasets, via REST API or MCP server. | API key / OAuth | ✅ | 🆓 free plan: $5/mo platform usage credit, no card required | docs |
| Bright Data GitHub 2,655★ brightdata/brightdata-mcp Smithery 300 uses SourceForge 4.4★/1 review | Access Web Unlocker, SERP API, Scraping Browser, and structured datasets via REST API or MCP to pull web data at scale. | API key | ✅ | 🆓 Free tier: 5,000 requests/month via the MCP server (renews on the 1st, no card required); other products pay-as-you-go | docs |
| Browse AI API | Trigger pre-built or custom 'robots' to extract and monitor web data via REST API, returning structured JSON. | API key | — | 🆓 free forever plan: 50 credits/mo, no card required | docs |
| Browser Use Cloud API | Launch cloud browser sessions and run AI browser-automation agent tasks via REST API or Python/TypeScript SDK. | API key | ✅ | $15 one-time signup credit for new accounts (Google/GitHub/Microsoft); paid usage afterward | docs |
| Browserbase (+ Stagehand) Smithery 433 uses SourceForge 3.0★/2 reviews | Run and control cloud headless browsers programmatically, with Stagehand adding natural-language page actions. | API key | ✅ | 🆓 Free tier: 1 browser hour/month, 3 concurrent browsers, 15 min/session, no card required | docs |
| Diffbot | Automatically extract structured data (articles, products, people) from any URL via REST API, no custom parsing rules needed. | API key | — | 🆓 free plan: 10,000 credits/mo, no card required (5 req/min limit) | docs |
| Firecrawl SourceForge 5.0★/1 review | Scrape, crawl, and extract structured data from any website via a single REST API call. | API key | ✅ | 🆓 free tier: 1,000 credits/mo, no card required | docs |
| Hyperbrowser GitHub 792★ hyperbrowserai/mcp | Spin up cloud browsers and call scrape, crawl, and structured-extract endpoints via REST API or MCP server. | API key | ✅ | 🆓 free plan: starter credits, 1 concurrent browser, no card required | docs |
| Oxylabs SourceForge 4.2★/1,211 reviews | Fetch web pages, search-engine results, and e-commerce data at scale via REST API with built-in proxy/unblocking infrastructure. | API key | ✅ | Trial: Web Scraper API free trial with up to 2,000 results one-time, no card required | docs |
| Playwright MCP (Microsoft) GitHub 37.5k★ microsoft/playwright-mcp | Official Microsoft MCP server giving agents structured browser control (click, type, navigate) via Playwright's accessibility tree. | none | ✅ | 🆓 free, open source, no key | docs |
| ScrapeGraphAI API | Use AI-driven prompts to scrape and extract structured data from webpages via REST API or Python/JS SDK. | API key | ✅ | Trial: 500 API credits one-time on the Free plan (10 requests/min), no card required | docs |
| ScraperAPI | Scrape any webpage with automatic proxy rotation, CAPTCHA handling, and JS rendering via a single REST API call. | API key | ✅ | 🆓 Free: free plan with 1,000 API credits per month (max 5 concurrent connections); new accounts start with a 7-day trial of 5,000 one-time credits, no card required | docs |
| Scrapfly | Scrape webpages, run cloud browsers, and capture screenshots via REST API or hosted MCP server with anti-bot bypass. | API key / OAuth | ✅ | 🆓 1,000 free credits/mo, no card required, no time limit | docs |
| ScrapingBee | Scrape any webpage with JS rendering, proxy rotation, and screenshot capture via a single REST API call. | API key | ✅ | Trial: 1,000 free API credits one-time on signup, no card required; then Hobby plan $19/mo for 75,000 credits | docs |
| Spider.cloud | Crawl and scrape websites at scale, returning JSON/XML/CSV, via REST API, CLI, or MCP server. | API key | ✅ | 🆓 Free: keyless /scrape endpoint, rate-limited (quota not published); other endpoints return 402 without a key | docs |
| Steel | Create managed cloud browser sessions with stealth proxies and CAPTCHA solving, controllable via REST API or Playwright/Puppeteer. | API key | ✅ | Trial: Launch plan is $0 + usage with $30 one-time usage credits valid 90 days (10 concurrent sessions, 60 requests/min); no Hobby plan | docs |
| Zyte API | Fetch and auto-extract web pages (HTML, browser rendering, product/article data) via one HTTP API with ban avoidance. | API key | — | Trial: $5 free credit one-time on signup, valid 30 days, no subscription needed; then pay-as-you-go or a monthly commitment | docs |
Knowledge and research data
Encyclopedias, academic papers, news, computational knowledge and up-to-date library documentation. — 16 services. JSON: catalog/knowledge-research.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| arXiv API GitHub 3,172★ blazickjp/arxiv-mcp-server Smithery 5,142 uses | Search arXiv preprints by keyword, author, category or ID and retrieve metadata, abstracts and PDF links. | none | ◐ | 🆓 free, no key | docs |
| Congress.gov API | Lets an agent look up U.S. bills, amendments, votes, members, committees, nominations and Congressional Record data from the Library of Congress. | API key | ◐ | 🆓 Free: government API, key issued instantly by email; 5,000 requests/hour. | docs |
| Context7 (library docs for agents) Smithery 5,563 uses | Fetch up-to-date, version-specific library documentation and code examples into a coding agent's context via MCP or REST. | API key | ✅ | 🆓 Free: 1,000 API calls per month with a free API key (low limits without key); Pro $10/seat/month | docs |
| Crossref REST API GitHub 117★ afrise/academic-search-mcp-server | Look up and search scholarly metadata such as DOIs, references, authors, funders and licenses across Crossref-registered works. | none | ◐ | 🆓 free, no key | docs |
| GDELT API GitHub 6★ cyanheads/gdelt-mcp-server | Full-text search global news in about 65 languages and analyze coverage volume, tone and geography in near real time. | none | ◐ | 🆓 free, no key | docs |
| Gitingest API | Lets an agent turn any public Git repository into a single text digest (summary, directory tree and file contents) sized for an LLM prompt. | none | ◐ | 🆓 No key needed: free public service; hosted API limited to 10 requests/minute per endpoint (the web UI also has rate limiting and CAPTCHA protection). | docs |
| Hacker News API GitHub 13.3k★ HackerNews/API GitHub 40★ pskill9/hn-server | Read Hacker News stories, comments, jobs, polls, user profiles and front-page rankings as real-time JSON. | none | ◐ | 🆓 free, no key | docs |
| Internet Archive Open Library API | Lets an agent search books, authors and subjects, fetch work/edition data by ISBN or OLID, search inside book texts and get cover images. | none | ◐ | 🆓 No key; free and open: 1 request/second anonymous, 3 requests/second with an identifying User-Agent. | docs |
| New York Times APIs | Lets an agent search NYT articles back to 1851, read top stories, most-popular lists, the Times Wire feed and bestseller lists. | API key | ◐ | 🆓 Free: all public APIs are free; 500 requests/day and 5 requests/minute per API. | docs |
| NewsAPI GitHub 3★ matteoantoci/mcp-newsapi | Search and retrieve current and historical news articles and top headlines from thousands of sources worldwide. | API key | ◐ | 🆓 free Developer plan: 100 req/day, dev/test only, 24h article delay | docs |
| OpenAlex API GitHub 57★ benedict2310/Scientific-Papers-MCP | Query an open catalog of scholarly works, authors, institutions, sources and topics, including citation data, via REST. | API key | ◐ | 🆓 free: $1 of API usage/day without payment method; free key raises daily budget 10x | docs |
| PubMed E-utilities (NCBI) GitHub 2,692★ openags/paper-search-mcp | Search, fetch, summarize and cross-link biomedical literature records from PubMed, PMC and other Entrez databases. | none | ◐ | 🆓 free; 3 req/s without key, 10 req/s with free NCBI API key | docs |
| Semantic Scholar API GitHub 165★ zongmin-yu/semantic-scholar-fastmcp-mcp-server | Search papers, authors and citation graphs, and get paper recommendations from Semantic Scholar's academic corpus. | API key | ◐ | 🆓 free; no key (shared, throttled pool) or free API key on request | docs |
| Wikidata | Query the Wikidata knowledge graph of entities, facts and relations via SPARQL, the REST API or MCP. | none | ✅ | 🆓 free, no key | docs |
| Wikipedia / Wikimedia API GitHub 295★ Rudra-ravi/wikipedia-mcp | Search, read and summarize Wikipedia and other Wikimedia content and metadata via REST and Action APIs. | none | ◐ | 🆓 free, no key (rate-limited) | docs |
| Wolfram|Alpha API | Get computed answers, structured data and step-by-step results for math, science and factual queries. | API key | ✅ | 🆓 Free: non-commercial developer AppID with up to 2,000 calls/month; paid for commercial use | docs |
Image generation and editing
Text-to-image, image editing, inpainting, upscaling and background removal. — 10 services. JSON: catalog/image-generation.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Adobe Firefly Services API | Generate and edit images and manage creative assets programmatically via Adobe's Firefly REST APIs. | OAuth 2.0 | ◐ | check pricing; requires Adobe Developer Console project and Firefly Services entitlement | docs |
| Black Forest Labs FLUX API | Generate, edit, and vary FLUX model images from text prompts via REST or the official OAuth MCP server. | API key | ✅ | paid only, no free tier (FLUX Schnell weights are open for self-hosting) | docs |
| Freepik API | Generate and edit images, and generate video, music and sound effects via REST API, plus access the Freepik stock asset library. | API key | ✅ | 🆓 free tier: ~5 EUR of free API credits, then pay-as-you-go | docs |
| Google Gemini / Imagen image API | Generate and multi-turn edit images from text via REST (Nano Banana/Imagen models), up to 4K with reference-image support. | API key | — | Paid only: pricing page lists Free Tier 'Not available' for all Gemini image models (Nano Banana family); usage-billed | docs |
| Ideogram API | Generate, edit, remix, upscale, and describe images via REST or an official OAuth MCP server, strong at in-image text. | API key | ✅ | Paid only: no free API credits (web app has 10 slow credits/week); API is pay-per-image from prepaid credit (min one-time purchase $1, min auto top-up target $10) | docs |
| Leonardo.Ai API SourceForge 5.0★/1 review | Generate images and videos from text via REST or the official MCP server, with model selection and job status polling. | API key | ✅ | Paid only: Pay-As-You-Go API credit (USD balance) via manual or auto top-ups; API access is separate from free/web app plans | docs |
| OpenAI Images API (gpt-image) GitHub 111★ SureScaleAI/openai-gpt-image-mcp | Generate, edit, and iteratively refine images from text prompts via REST, with mask-based inpainting and streaming previews. | API key | ◐ | paid only; no free image credits, usage-based billing | docs |
| Recraft API GitHub 60★ recraft-ai/mcp-recraft-server | Generate, edit, upscale, and vectorize images via REST API using Recraft's proprietary models. | API key | ✅ | paid only; pay-per-image (from $0.007/image on V4.1 Flash), no confirmed free credits | docs |
| remove.bg API | Remove image backgrounds programmatically via a simple REST API with JSON or multipart uploads. | API key | — | 🆓 Free: first 50 API calls per month, then paid credits | docs |
| Stability AI Platform API | Generate, upscale, and edit images via REST (Stable Image Ultra/Core/SD3 models) using simple credit-based billing. | API key | ◐ | 25 free credits on signup, then pay-as-you-go | docs |
Video generation and editing
Text/image-to-video models, talking avatars, programmatic video rendering and video hosting. — 14 services. JSON: catalog/video-generation.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Akool API | Generate face-swap, talking avatar, and video-translation content programmatically via REST API. | API key | — | 🆓 Paid only for API: API access starts at the Pro Max plan; the Free plan is web-app only with full-screen watermark | docs |
| Creatomate API | Programmatically generate and render videos/images from templates via REST API. | API key | ✅ | Trial: full-featured trial with 50 credits one-time on signup, no credit card required; then Essential plan with 2,000 credits/mo | docs |
| D-ID API | Animate photos into talking-head videos with lip-sync from text or audio via REST API. | API key | ✅ | Trial: 14 days with 3 minutes of video credits, then paid plans only (API price per minute not published in machine-readable form) | docs |
| Google Veo (Gemini API / Vertex AI) | Generate video from text or image prompts via Gemini API (api key) or Vertex AI (cloud IAM), incl. Veo 3.1 scene extension. | API key / OAuth | ✅ | no free tier for video; Veo generation requires a paid Gemini API / Vertex AI billing account | docs |
| HeyGen API SourceForge 2.0★/1 review | Create AI avatar/talking-head videos from text or audio, manage avatars and voices, via REST API. | API key / OAuth | ✅ | no free API credits since Feb 2026; pay-as-you-go from $5, $0.50-$0.99/credit. Free plan (3 videos/mo) exists but is for the web app, not standalone API. | docs |
| Klap API | Automatically turn long videos into short clips with captions and reframing via REST API. | API key | — | Paid only; usage-based, billed monthly per operation (Generate Short $0.32, Video Input $0.44, Export $0.48); no free API credits stated | docs |
| Kling AI API GitHub 41★ 199-mcp/mcp-kling | Generate text-to-video, image-to-video, lip-sync and video effects via REST API with a Bearer API key. | API key | ◐ | Paid only; prepaid credit packages from $0.14/unit, e.g. 5,000 units/$700, 180-day validity; a Trial Resource Package for integration testing is offered | docs |
| Luma AI Dream Machine API GitHub 26★ lumalabs/luma-api-mcp | Generate and extend AI videos from text or start/end keyframe images via async REST API (Ray 3.2). | API key | ✅ | Paid only; pay per video, e.g. Ray 3.2 5s text/image-to-video $0.15 (540p) / $0.30 (720p) / $1.20 (1080p), $5,000/mo cap on default Build tier | docs |
| MiniMax Hailuo API GitHub 1,585★ MiniMax-AI/MiniMax-MCP | Async text-to-video, image-to-video and subject-reference video generation via REST API, up to 1080p. | API key | ✅ | new accounts get 50 signup credits (~1 short clip); 5s video costs ~45-70 credits, 1000 credits=$1 | docs |
| PixVerse API GitHub 52★ PixVerseAI/PixVerse-MCP | Generate text-to-video, image-to-video, transition and fusion clips (360p-1080p) via REST API. | API key | ✅ | Paid only; prepaid credits from $10, $1 = 5 videos (v6, 720p, 5s, no audio) | docs |
| Runway API | Generate and edit images/video (Gen-4.5) via async task-based REST API: submit, poll, download. | API key | ✅ | no free tier; $10 minimum credit top-up, $0.01/credit | docs |
| Shotstack API | Compose Edit JSON timelines to programmatically render, edit, and template videos, images and audio. | API key | ✅ | Trial: 10 free credits one-time (valid 30 days), then pay-as-you-go or subscription; stage sandbox (https://api.shotstack.io/edit/stage) for development, v1 production without watermarks | docs |
| Synthesia API SourceForge 5.0★/1 review | Generate AI avatar talking-head videos from text scripts via REST API; supports custom avatars and voices. | API key | ✅ | Paid only; API access requires the Creator plan or above | docs |
| Tavus API | Create AI video replicas and real-time conversational video agents (CVI) via REST API. | API key | ✅ | 🆓 Free tier: Free plan with 25 min of conversational video and 5 min of video generation per month, full API access, 25 stock replicas; Starter $59/mo | docs |
Speech and audio
Text-to-speech, speech-to-text, voice cloning, dubbing and audio intelligence. — 13 services. JSON: catalog/audio-speech.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Amazon Polly / Amazon Transcribe (AWS) | Convert text to lifelike speech (Polly) and transcribe audio with speaker diarization (Transcribe) via AWS API. | cloud IAM | ✅ | 🆓 Free tier: Polly 5M chars/mo standard (neural 1M, generative 100K chars/mo for first 12 months), Transcribe 60 min/mo (12 months); new AWS accounts since 2025-07-15 get up to $200 Free Tier credits | docs |
| AssemblyAI API | Transcribe recorded or streaming audio with speaker diarization, sentiment analysis and LLM-based audio insights via REST. | API key | — | Trial: $50 in free credits one-time on signup, no card required, credits do not expire (LLM Gateway not included); then pay-as-you-go | docs |
| Azure AI Speech GitHub 1★ microsoft/azure-speech-mcp-server | Convert text to speech, transcribe speech to text and translate speech via REST or Speech SDK. | cloud IAM | ✅ | 🆓 Free tier (F0): 5 audio hrs/mo STT, 0.5M chars/mo neural TTS; batch transcription not available on F0 | docs |
| Cartesia API | Generate low-latency real-time text-to-speech, transcribe speech and clone voices via REST/WebSocket API. | API key | ✅ | 🆓 Free tier: 20,000 credits/mo; no commercial-use license and no voice cloning | docs |
| Deepgram API GitHub 2★ deepgram/mcp | Transcribe batch or streaming audio with diarization, synthesize speech, and run real-time voice agents via REST/WebSocket. | API key | ✅ | Trial: $200 in free credit one-time on signup, no credit card required; then pay-as-you-go | docs |
| ElevenLabs API GitHub 1,537★ elevenlabs/elevenlabs-mcp SourceForge 4.0★/4 reviews | Generate, clone and stream text-to-speech voices and transcribe audio via REST/WebSocket API. | API key | ✅ | 🆓 Free: limited monthly credits; non-commercial use with attribution only, no voice cloning | docs |
| Google Cloud Text-to-Speech / Speech-to-Text | Synthesize lifelike speech from text and transcribe audio to text via REST/gRPC using GCP credentials. | cloud IAM | ✅ | 🆓 Free tier: TTS 4M chars/mo Standard and WaveNet, 1M chars/mo Neural2, Chirp 3 HD and Studio; STT 60 min/mo | docs |
| Hume AI API | Generate expressive text-to-speech and run real-time empathic voice conversations (EVI) via REST/WebSocket. | API key | ✅ | 🆓 Free tier: 10,000 TTS chars/mo + 5 EVI min/mo; new accounts also get $20 in credits | docs |
| Murf AI API SourceForge 5.0★/7 reviews | Generate AI voiceovers, clone voices and dub audio in 35+ languages via REST API. | API key | ✅ | Trial: 100,000 characters one-time on the free API plan, no time limit | docs |
| OpenAI Audio API (TTS / transcription) GitHub 2,524★ openai/openai-openapi | Synthesize speech with TTS models and transcribe or translate audio with Whisper/GPT-4o transcribe via REST. | API key | — | paid only (pay-per-use) | docs |
| Resemble AI API SourceForge 1.7★/3 reviews | Synthesize speech, clone voices, convert speech-to-speech and detect deepfake audio via REST API. | API key | — | Paid only; Flex plan is $0/mo base with pay-as-you-go credits, no free usage allowance stated | docs |
| Rev AI API | Submit audio for asynchronous or streaming speech-to-text transcription, plus sentiment and topic extraction, via REST. | API key | — | trial credits (about 5 hours of ASR) | docs |
| Speechmatics API | Transcribe audio in batch or real time with speaker diarization across many languages via REST/WebSocket. | API key | ◐ | Trial: one-time $100 credit grant, no payment card required | docs |
Music generation
Generate songs, instrumentals, loops and sound effects from prompts. — 6 services. JSON: catalog/music-generation.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Beatoven.ai API SourceForge 3.8★/4 reviews | Generate royalty-cleared background music and sound effects from text prompts via REST API (Maestro). | API key | — | check pricing | docs |
| ElevenLabs Music API GitHub 1,537★ elevenlabs/elevenlabs-mcp | Generate original music tracks from text prompts or detailed composition plans via REST API, with commercial licensing. | API key | ✅ | 🆓 Free tier: 10,000 credits per month shared with TTS (music included, no commercial use of music on Free; Starter $6/mo or higher needed) | docs |
| Loudly API SourceForge 1.0★/1 review | Generate, remix, stem-split, and master music tracks programmatically via REST API. | API key | — | Trial: free track allowance on signup with the API key from the developer portal; then volume-based pricing (Startup/SME/Corporate) or pay-as-you-go | docs |
| Mubert API | Generate streaming or file-based background music from text/image prompts via REST/WebRTC API, 15s-25min tracks. | API key | — | paid only; plans start at $49/mo (100 generations/mo), no free tier | docs |
| Soundraw API SourceForge 1.0★/1 review | Generate royalty-free background music tracks by mood, genre, and duration via REST API for embedding in apps. | API key | — | Trial: one-time 2-week free API trial with no commitment; then Starter $29.99/mo for 100 songs with a 6-month minimum commitment | docs |
| Stable Audio API (Stability AI) | Generate music and sound effects from text prompts via REST API (Stable Audio 2.5, or Stable Audio 3.0 for tracks up to 6 minutes). | API key | — | shares Stability AI platform credits; 25 free credits on signup, then pay-as-you-go | docs |
3D generation and assets
Text/image-to-3D mesh generation, texturing and 3D asset libraries. — 7 services. JSON: catalog/3d-generation.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| CSM (Common Sense Machines) API | Create 3D assets and multi-part kits from images via async REST sessions (image-to-3D, retopology). | API key | — | Unavailable: service appears discontinued | docs |
| Hyper3D Rodin API | Generate 3D meshes from text or images (sketch/regular/detail quality tiers) via an async REST job API. | API key | — | Paid only: API access requires the Business plan ($120/mo, $96/mo billed annually) or Enterprise; direct credits $1.5 each | docs |
| Meshy API GitHub 48★ meshy-dev/meshy-mcp-server | Generate, retexture, rig, and animate 3D models from text or images via REST API or official MCP server. | API key | ✅ | Paid only: creating API keys requires a paid plan (Pro $20/mo+); Free accounts get only a built-in test key for the Playground (free web plan 100 credits/mo) | docs |
| Sketchfab Data API GitHub 40★ gregkop/sketchfab-mcp-server | Search, download, and upload 3D models on Sketchfab programmatically via the REST Data API v3. | API key / OAuth | ◐ | 🆓 Free: no key needed for search and model listing (GET /v3/search, /v3/models); downloads (/v3/models/{uid}/download) need a free account token | docs |
| Stability AI 3D (Stable Fast 3D / SPAR3D) API | Convert a single 2D image into a textured 3D mesh (GLB) via the v2beta/3d REST endpoints. | API key | — | 25 free credits on signup, then pay-as-you-go (Stable Fast 3D costs 10 credits ~ $0.10/generation) | docs |
| Tencent Hunyuan3D API | Generate textured 3D meshes (GLB, PBR) from text, images, or sketches via Tencent Cloud's Hunyuan 3D API. | cloud IAM | — | Trial: 200 free credits one-time on first activation (valid 1 year); then postpaid $0.02/credit, Professional generation 25 credits (~$0.50), Express 15 | docs |
| Tripo API GitHub 206★ VAST-AI-Research/tripo-mcp | Generate textured 3D meshes from text or images via REST API, with an official MCP server for agents. | API key | ✅ | Trial: one-time free credits on first API key (amount varies by signup path, not listed on the pricing page); then pay-as-you-go at $0.01/credit | docs |
Architecture, CAD and BIM
Building information models, CAD geometry, construction management and GIS platforms with programmatic access. — 8 services. JSON: catalog/architecture-cad-bim.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Autodesk Platform Services (APS) | Upload, translate, view and automate CAD/BIM files (Model Derivative, Data Management, Design Automation) via REST APIs. | OAuth 2.0 | ✅ | 🆓 Free tier: limited usage of rated APIs (Automation, Model Derivative, Flow Graph Engine, Reality Capture) per month, renews monthly; Pay as You Go beyond that needs a card or PayPal | docs |
| Bentley iTwin Platform APIs | Create, manage and query digital twins, iModels and reality/reporting data for infrastructure projects via REST APIs. | OAuth 2.0 | — | 🆓 Free tier: Community plan with 100 credits/month, 10 GB cloud data, 100 GB reality data; non-commercial, non-production use only; no expiry | docs |
| Onshape REST API | Create, read and modify Onshape CAD documents, parts, assemblies and drawings programmatically via REST API. | API key / OAuth | ✅ | 🆓 free tier (public documents only); private documents need a paid plan | docs |
| Procore API SourceForge 5.0★/2 reviews | Read and write construction project data - RFIs, submittals, drawings, budgets, schedules - via REST API. | OAuth 2.0 | ✅ | 🆓 free developer sandbox; production requires customer's paid Procore plan | docs |
| Rhino.Compute (McNeel) | Run Rhino/Grasshopper geometry operations headlessly via a stateless REST API you deploy yourself. | API key | — | Paid only: self-hosted, requires a Rhino license; core-hour billing at $0.10 per core per hour of Rhino uptime on Windows Server, no free allowance | docs |
| Speckle API | Send, receive and query 3D/BIM model data across CAD tools (Revit, Rhino, Grasshopper, Tekla) via GraphQL API and SDKs. | API key / OAuth | ◐ | 🆓 free Explore plan (1 project, 3 users), unlimited API calls | docs |
| Trimble Connect API | Manage Trimble Connect projects, files, BIM models, issues/topics and metadata via REST APIs (Core, Model, Organizer). | OAuth 2.0 | — | check pricing | docs |
| Zoo Text-to-CAD API (KittyCAD) | Generate 3D CAD models from text prompts and run modeling/file-conversion operations via REST API. | API key | ✅ | start free trial credits, then usage-based pay-as-you-go | docs |
Diagrams and software architecture
Render or edit diagrams (Mermaid, PlantUML, C4), whiteboards and architecture models. — 9 services. JSON: catalog/diagrams-software-architecture.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Eraser API (DiagramGPT) | Generate diagrams from text prompts (DiagramGPT) and manage Eraser files programmatically via REST API. | API key | ✅ | paid only - API tokens require an active paid team plan | docs |
| IcePanel API SourceForge 5.0★/1 review | Programmatically create, read, import, and export C4-style architecture landscapes and models via REST API. | API key | ✅ | 🆓 free tier: 10,000 read requests/mo, 1,000 write requests/mo, 5 import/export requests/mo | docs |
| Kroki | Render 25+ diagram-as-code formats (PlantUML, Mermaid, C4, GraphViz, BPMN, etc.) from text via a free HTTP GET/POST API. | none | — | 🆓 free, no key; public hosted instance at kroki.io sponsored by Exoscale (no SLA) | docs |
| Lucid (Lucidchart) REST API | Create, read, search, and manage Lucidchart documents and folders programmatically via REST API. | API key / OAuth | ✅ | check pricing | docs |
| Mermaid Chart API | Validate, render, and save Mermaid diagrams via Mermaid Chart's official MCP server using an account API token. | API key | ✅ | 🆓 unauthenticated MCP validate/render tools are free; saving to a Mermaid Chart account needs a token, check pricing for limits | docs |
| Miro REST API | Create/read boards and items via REST API, or use Miro's official MCP server to search, build, and summarize boards. | OAuth 2.0 | ✅ | 🆓 Free tier: up to 3 editable team boards; MCP on all plans, capped per day at 100 tool calls on Free (Starter 500, Business 2,000, Enterprise 10,000) | docs |
| Napkin AI API | Generate diagrams, flowcharts, mind maps, and charts from text via REST API, exporting to SVG, PNG, or PPT. | API key | — | 🆓 included on every plan; any account can create a token and call the API, limited by credits | docs |
| PlantUML Server API | Render UML and architecture-as-code diagrams to PNG/SVG/ASCII via a free public HTTP GET API using encoded diagram text. | none | — | 🆓 free, no key; public hosted server at plantuml.com/plantuml | docs |
| Structurizr | Create and update C4-model software architecture diagram workspaces as JSON via a signed HTTPS API. | API key | ✅ | 🆓 free tier: workspaces up to 0.5MB; paid plans raise the limit to 5MB | docs |
Design and UI
Read and write design files, generate branded graphics and publish websites. — 6 services. JSON: catalog/design-ui.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Canva Connect API | Programmatically create, autofill, and export Canva designs, and manage assets and comments via a REST API. | OAuth 2.0 | ✅ | check pricing (free to build/test; public apps require Canva review before production use) | docs |
| Figma REST API / Dev Mode MCP GitHub 219★ figma/rest-api-spec | Read and write Figma file/comment/component data via REST, and feed live design context to coding agents via the official Dev Mode MCP server. | API key / OAuth | ✅ | 🆓 free: personal access tokens work on free plan, rate-limited per seat/plan tier; MCP free during beta | docs |
| Framer SourceForge 4.0★/1 review | Automate publishing of Framer sites programmatically (get project info, publish previews, promote to production) via a Node SDK. | API key | — | 🆓 Free: Server API is free while in beta; Framer plans per-use pricing with a monthly free allowance later | docs |
| Penpot API SourceForge 5.0★/1 review | Read, create, and modify Penpot design files, comments, and webhooks via a token-authenticated RPC/REST API, or via the official MCP server. | API key | ✅ | 🆓 free tier: free cloud account (design.penpot.app) plus free, open-source self-hosting | docs |
| v0 Platform API (Vercel) | Generate full UI/frontend code from natural-language prompts, iterate via chat, and deploy the result directly to Vercel via REST API. | API key | ✅ | 🆓 Free tier: v0 Free plan includes $5 of credits per month (7 messages/day); Platform API use on Free not confirmed, credits also included on Premium/Team plans | docs |
| Webflow Data API | Create/update CMS collections, items, and pages, and publish Webflow sites programmatically via REST API or the official MCP server. | API key / OAuth | ✅ | check pricing (API access itself is free with a token; some CMS/publish actions require the site to be on a paid Webflow plan) | docs |
Documents, OCR and presentations
Parse PDFs and scans, convert file formats, generate slides and collect e-signatures. — 14 services. JSON: catalog/presentations-documents.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Adobe PDF Services API | Programmatically create, convert, combine, compress, OCR, and extract data from PDF documents. | OAuth 2.0 | — | 🆓 free tier: 500 document transactions/month, no credit card required | docs |
| AWS Textract GitHub 0★ ag2-mcp-servers/amazon-textract | Detect and extract text, forms, tables, and data from scanned documents and images via API calls. | cloud IAM | ✅ | Trial: new AWS customers get 3 months free, per month 1,000 pages DetectDocumentText, 100 pages AnalyzeDocument forms/tables/layout/queries, 100 AnalyzeExpense/AnalyzeID, 2,000 pages AnalyzeLending; card required | docs |
| Azure AI Document Intelligence | Analyze forms, invoices, receipts, and scanned documents to extract structured JSON via REST API. | cloud IAM | — | 🆓 Free tier: F0 pricing tier, 500 pages/month; analyzes only the first 2 pages per document, 4 MB max file, 1 TPS | docs |
| CloudConvert API SourceForge 5.0★/1 review | Convert, compress, merge, watermark, and OCR files across 200+ formats via REST API or MCP. | API key / OAuth | ✅ | 🆓 Free: 10 conversion credits/day including all API features, no credit card required; paid credit packages beyond that; free Sandbox API for unlimited test jobs without consuming credits | docs |
| DocuSign eSignature API GitHub 24★ docusign/OpenAPI-Specifications | Send, sign, track, and manage electronic signature envelopes and agreement workflows via REST API. | OAuth 2.0 | ✅ | 🆓 free developer/demo sandbox account (account-d.docusign.com) with unlimited test envelopes; production use requires a paid DocuSign plan | docs |
| Gamma API | Generate, poll, and export AI-made presentations, documents, or social posts as PDF/PPTX via REST API. | API key / OAuth | ✅ | Paid only for API keys (Pro, Ultra, Teams or Business plan); the Gamma MCP server/connectors work on all plans including Free, with generations consuming credits | docs |
| Google Document AI | Extract text, tables, and structured data from documents like invoices, forms, and IDs via REST API. | cloud IAM | — | 🆓 Free tier: first 1,000 pages/month free for Enterprise Document OCR only (then $1.50/1,000); Form Parser and custom extractor $30/1,000 pages with no free band | docs |
| Google Slides / Docs API | Read and programmatically edit Google Slides presentations (slides, shapes, text, tables) via REST API or MCP. | OAuth 2.0 | ✅ | 🆓 free, no key (standard Google API usage quotas apply; requires GCP project + OAuth consent) | docs |
| LlamaParse (LlamaCloud) | Parse, classify, extract, and split complex documents (tables, forms, charts) into LLM-ready structured data via API. | API key | ✅ | 🆓 Free tier: Free plan with 10K credits/month; beyond that credit-based at $1.25/1,000 credits (1-45+ credits/page depending on tier); 48h parse cache is free to re-query | docs |
| Mistral OCR API GitHub 0★ D-Diaa/mistral-ocr-mcp | Extract text, tables, and layout structure from PDFs and images as structured Markdown/JSON via REST API. | API key | ◐ | 🆓 Free tier: Free plan includes $10/month in API credits; then $4/1,000 pages (OCR), $5/1,000 pages (Document AI); 50% off via Batch API | docs |
| PDF.co API | Convert, merge, split, edit, fill forms, OCR, and extract data from PDFs via REST API. | API key | ✅ | trial credits: 10,000 credits for 1 month, no credit card required | docs |
| Reducto API | Parse, extract, split, edit, and classify complex documents into structured JSON/Markdown via REST API or SDKs. | API key | ✅ | Trial: $150 in free credits (15,000 credits) one-time for new Standard accounts; then standard rates; Startup Program gives extra credits to qualifying teams | docs |
| SlideSpeak API GitHub 14★ SlideSpeak/slidespeak-mcp SourceForge 1.0★/1 review | Generate, edit, and download PowerPoint/PDF presentations from text, documents, or outlines via REST API. | API key | ✅ | Trial: free API trial, no credit card required; then API plans from $49/month (1,000 credits) | docs |
| Unstructured API GitHub 43★ Unstructured-IO/UNS-MCP | Partition and extract structured elements (text, tables, layout) from PDFs, docs, and images for RAG pipelines via API. | API key | ✅ | Trial: 10,000 free pages one-time on signup, no credit card; then pay-as-you-go at $0.015/page | docs |
Translation and language
Machine translation, grammar and style checking. — 6 services. JSON: catalog/translation-language.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Amazon Translate SourceForge 5.0★/1 review | Translate text and documents in real time or batch across 75+ languages via the AWS SDK/API. | cloud IAM | ✅ | 🆓 free tier: 2M characters/month for 12 months (new AWS accounts) | docs |
| Azure AI Translator | Translate text, detect language, and transliterate across 100+ languages via REST API within Azure AI Services. | API key | ◐ | 🆓 free tier (F0): 2,000,000 characters/month | docs |
| DeepL API GitHub 116★ DeepL/deepl-mcp-server SourceForge 4.0★/1 review | Translate and rephrase text or documents between 30+ languages via REST API, SDKs, or an official MCP server. | API key | ✅ | Paid only for new signups: API Free plan retired mid-2026; API plans are Developer (from EUR 4.99/mo, 'test out the API for free'), Growth and Enterprise API; legacy Free keys (suffix :fx) use https://api-free.deepl.com | docs |
| Google Cloud Translation | Translate text/documents and detect language across 100+ languages via REST/gRPC API within Google Cloud. | cloud IAM | ◐ | 🆓 free tier: 500,000 characters/month (permanent, not a trial) | docs |
| LanguageTool API SourceForge 5.0★/1 review | Check grammar, style, and spelling in 30+ languages via a public HTTP API, with an optional Premium key for higher limits. | API key | ◐ | 🆓 Free: no key needed on public endpoint (rate-limited: 20 req/min, 75KB text/min per IP, 20KB per request) | docs |
| Lara Translate API | Translate text, documents, images and audio with context, style, glossaries and translation memories, and detect the language of text. | API key | ✅ | 🆓 Free: 10,000 API characters/month (shared by translation and language detection), no credit card required | docs |
Code execution sandboxes
Isolated cloud environments where an agent can run code, shells and whole dev environments safely. — 10 services. JSON: catalog/code-execution-sandbox.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Cloudflare Sandbox SDK | Deploy a Cloudflare Worker embedding this SDK to run untrusted code in per-request container sandboxes. | API key | ✅ | requires Workers Paid plan ($5/mo) for Containers; no free tier for container-backed sandboxes | docs |
| CodeSandbox SDK | Programmatically create, resume, and control cloud VM sandboxes to run and preview AI-written code. | API key | — | 🆓 Free plan: 400 VM credits/mo (~40 Nano-VM hrs), up to 10 concurrent VMs | docs |
| Daytona | Create elastic remote sandboxes via SDK/API to run AI-generated code with sub-second startup. | API key | ✅ | Trial: $200 free compute credit one-time on signup, no credit card required; first 5 GiB storage free; startup program up to $50k credits | docs |
| E2B GitHub 394★ e2b-dev/mcp-server | Spin up isolated Firecracker cloud sandboxes via SDK/REST to execute AI-generated code and return results. | API key | ✅ | Trial: one-time $100 usage credit on signup (Hobby, no card); up to 1 h per sandbox, 20 concurrent; then pay-as-you-go | docs |
| Judge0 | Submit source code and stdin via REST to compile/run it in 60+ languages and poll for the result. | API key | — | Paid only on Judge0 Cloud (Pro EUR 27/mo for 2,000 submissions/day and up); self-host free & open-source (GPLv3) | docs |
| Modal GitHub 1★ milkymap/mcp4modal_sandbox | Programmatically launch serverless sandboxes, optionally with GPUs, to execute untrusted or agent code. | API key | ◐ | 🆓 Starter plan: $0 base + $30/mo free credits | docs |
| Piston GitHub 2,823★ engineer-man/piston | Call a free public REST API to compile and run code in 70+ languages inside isolated containers. | API key | — | 🆓 Free: self-host (open source); public emkc.org API no longer open since 2026-02-15, token only for non-commercial educational projects | docs |
| Riza | Call a REST API to execute untrusted Python/JS/Ruby/PHP code in sandboxes that start in under 10ms. | API key | ✅ | 🆓 Free tier: Hobby plan free forever, 100,000 requests/month, 30 s execution limit; then usage-based pricing | docs |
| Runloop | Create, snapshot, suspend/resume, and run commands in Linux Devboxes via API/SDK for agent coding tasks. | API key | ✅ | $50 free credits on signup, then usage-based ($0.108/CPU-hr, $0.0252/GB-hr) | docs |
| Vercel Sandbox | Boot ephemeral Firecracker microVMs via SDK/REST to run agent- or AI-generated code and shell commands. | API key / OAuth | ✅ | 🆓 usage included on Hobby plan, otherwise usage-based on Pro/Enterprise | docs |
Developer platforms and DevOps
Source control, CI/CD, monitoring, error tracking, incident management and package registries. — 12 services. JSON: catalog/developer-devops.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| CircleCI API GitHub 94★ CircleCI-Public/mcp-server-circleci SourceForge 3.0★/2 reviews | An agent can trigger pipelines, rerun workflows, fetch logs/test results, and validate CI/CD configuration via REST. | API key | ✅ | 🆓 free plan: 30,000 credits/month (~6,000 build minutes on a small Docker resource class), credits expire monthly | docs |
| Datadog API SourceForge 4.9★/7 reviews | An agent can query metrics, logs, traces, monitors, and dashboards, and manage Datadog configuration via REST. | API key | ✅ | 🆓 free Infrastructure Monitoring plan: 1-day metric retention, up to 5 hosts; other products (APM, Logs, Security) are paid | docs |
| Docker Hub API GitHub 165★ docker/hub-mcp | An agent can search, push, pull, tag, and manage container images and repositories on Docker Hub. | API key | ✅ | 🆓 free personal accounts with rate-limited image pulls; paid Pro/Team/Business tiers raise pull limits | docs |
| GitHub API GitHub 33.2k★ github/github-mcp-server Smithery 6,059 uses SourceForge 4.7★/21 reviews | An agent can manage repositories, issues, pull requests, releases, and code search via REST or GraphQL. | API key / OAuth | ✅ | 🆓 free with any GitHub account; 5,000 req/hr authenticated, 60/hr unauthenticated | docs |
| GitLab API SourceForge 4.4★/14 reviews | An agent can manage projects, issues, merge requests, CI/CD pipelines, and repository files via REST/GraphQL. | API key / OAuth | ✅ | 🆓 free tier: full REST API access on GitLab.com Free plan; some features gated to Premium/Ultimate | docs |
| Globalping Network Measurement API | Lets an agent run ping, traceroute, MTR, DNS and HTTP tests from thousands of probes worldwide to check reachability, latency and routing of a host. | none | ✅ | 🆓 No key; 250 tests/hour anonymously (up to 50 probes per measurement), 500 tests/hour with a free account token (up to 500 probes); extra tests use credits. | docs |
| Maven Central Search API | Lets an agent search Maven Central for Java/JVM artifacts by groupId, artifactId, class name or SHA-1 and look up the latest versions before adding a dependency. | none | ◐ | 🆓 No key; free public API with no published quota (fair use). | docs |
| PagerDuty API GitHub 34★ PagerDuty/api-schema GitHub 79★ PagerDuty/pagerduty-mcp-server SourceForge 4.7★/44 reviews | An agent can create/manage incidents, on-call schedules, escalation policies, and services via REST. | API key / OAuth | ✅ | 🆓 free plan for up to 5 users: 100 monthly SMS/phone notifications, 1 on-call schedule, 1 escalation policy, API access | docs |
| Postman API Smithery 3 uses SourceForge 4.8★/24 reviews | An agent can manage Postman collections, workspaces, environments, mocks, monitors, and API specs via REST. | API key | ✅ | 🆓 Free plan: 10,000 Postman API calls/month; rate limits ~300 req/min general, stricter for specific endpoints | docs |
| Reflag Management API | Lets an agent create feature flags, change their targeting for users and companies, and evaluate flags at runtime. | API key / OAuth | ✅ | 🆓 Free Starter plan: 1,000 monthly tracked users, unlimited seats, 3 environments; no overage (upgrade required) | docs |
| Sentry API Smithery 35 uses | An agent can query and triage error/performance issues and manage projects, releases, and org data. | API key / OAuth | ✅ | 🆓 free Developer plan: 1 user, 5,000 errors/mo, 5GB logs, 50 replays; includes MCP access | docs |
| Supabase Management API | An agent can programmatically create and manage Supabase projects, databases, API keys, and config. | API key / OAuth | ✅ | 🆓 free plan available; rate limit 120 req/min per user/project (lower for heavier endpoints) | docs |
Cloud and hosting
Cloud providers, serverless and edge platforms, and site hosting an agent can deploy to and manage. — 10 services. JSON: catalog/cloud-hosting.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| AWS APIs GitHub 9,728★ awslabs/mcp | An agent can provision and control thousands of AWS resources (compute, storage, databases, ML) via SDKs/CLI/REST. | cloud IAM | ✅ | 🆓 Free tier: 30+ services always free within monthly limits; new accounts also get up to $200 one-time credits ($100 on signup + up to $100 earned) usable over 6 months | docs |
| Azure APIs GitHub 3,094★ Azure/azure-rest-api-specs GitHub 3,707★ microsoft/mcp | An agent can deploy and manage Azure resources (compute, storage, databases, AI) across resource-provider REST APIs. | cloud IAM | ✅ | 🆓 12 months of select free services plus $200 credit for 30 days for new accounts; many services also have a permanent always-free monthly amount | docs |
| Cloudflare API Smithery 199 uses SourceForge 4.6★/12 reviews | An agent can manage DNS, Workers, zones, WAF/security rules, and caching for Cloudflare accounts programmatically. | API key / OAuth | ✅ | 🆓 free with any Cloudflare account; API access itself is free, manages both free and paid Cloudflare products | docs |
| Fly.io Machines API | An agent can create, start, stop, and destroy Fly.io Machines (lightweight VMs) programmatically via REST. | API key | ✅ | Trial: 2 machine-hours or 7 days, whichever comes first, no card needed to start (adding a card ends the trial); then pay-as-you-go, no perpetual free tier | docs |
| Google Cloud APIs GitHub 16.5k★ googleapis/mcp-toolbox | An agent can create and manage Google Cloud resources (compute, storage, data, AI/ML) via REST, gRPC, or client libraries. | cloud IAM | ✅ | 🆓 free trial credit for new customers plus an Always Free tier with perpetual no-cost limits on select products | docs |
| Mux Video API | Upload, encode, stream and analyse video; get playback URLs, thumbnails and captions via REST. | API key | ✅ | 🆓 first 100,000 delivered minutes/month free, then usage-based | docs |
| Netlify API SourceForge 4.0★/5 reviews | An agent can create/manage sites, trigger and monitor deploys, and configure DNS, domains, and env vars. | API key / OAuth | ✅ | 🆓 Free: $0 forever plan with 300 credits per month (hard limit, no rollover); API usage subject to account plan limits | docs |
| Render API | An agent can create and manage Render services, trigger deployments, and configure databases and env vars. | API key | ✅ | 🆓 free static sites; free web services that spin down after inactivity | docs |
| Tencent EdgeOne Pages (Makers) | Lets an agent deploy HTML pages, static sites and full-stack apps with edge functions to EdgeOne and get back a public URL. | API key | ✅ | 🆓 Free plan (stated as permanent): 40 projects, 500 builds/month, 3M Edge Function and 1M Cloud Function invocations/month, 5 GB storage, 1 GB KV, 1 GB Blob. | docs |
| Vercel API Smithery 549 uses SourceForge 4.5★/2 reviews | An agent can create deployments, manage projects/domains/env vars, and query analytics and logs. | API key / OAuth | ✅ | 🆓 free on Hobby plan; some resources/endpoints require Pro/paid plan | docs |
Databases
Managed SQL, NoSQL, key-value and analytics databases an agent can create, query and manage. — 12 services. JSON: catalog/databases.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| ClickHouse Cloud GitHub 879★ ClickHouse/mcp-clickhouse | Run SQL analytics queries and manage Cloud services/backups via REST API or official MCP server. | API key | ✅ | no permanent free tier; 30-day trial with $300 credits | docs |
| Convex GitHub 12.6k★ get-convex/convex-backend | Introspect tables/functions, call functions, and read/write data in a reactive database via MCP or client SDKs. | API key | ✅ | 🆓 generous free tier for small apps, zero cost/maintenance | docs |
| Google BigQuery Smithery 6,986 uses | Run SQL queries and inspect datasets/tables in BigQuery via REST API or the fully-managed remote MCP server. | cloud IAM | ✅ | 🆓 Free tier: 1 TiB of querying and 10 GiB of storage per month | docs |
| MongoDB Atlas GitHub 1,137★ mongodb-js/mongodb-mcp-server SourceForge 5.0★/1 review | Create/manage Atlas clusters and query MongoDB data via Admin API, drivers, or official MCP server. | API key / OAuth | ✅ | 🆓 free tier: M0 cluster free forever (512MB) | docs |
| Neon Postgres GitHub 650★ neondatabase/mcp-server-neon | Provision and manage serverless Postgres projects/branches and run SQL via REST API or MCP server. | API key / OAuth | ✅ | 🆓 Free tier: 100 projects; 0.5 GB storage, 100 CU-hours and 5 GB egress per project per month, no card required | docs |
| PlanetScale Smithery 2 uses | Manage MySQL databases, branches, and schema, and view Insights via hosted MCP server or API. | API key / OAuth | ✅ | Paid only: no free or Hobby plan; cheapest is Postgres PS-5 single node at $5/month | docs |
| Snowflake GitHub 299★ Snowflake-Labs/mcp SourceForge 4.8★/4 reviews | Run SQL, Cortex Analyst, and Cortex Search over warehoused data via REST API or managed MCP server. | API key / OAuth | ✅ | trial credits (no permanent free tier); check pricing | docs |
| Supabase Smithery 189 uses | Manage Postgres tables, auth, storage, and edge functions via REST/GraphQL APIs or client SDKs. | API key / OAuth | ✅ | 🆓 free tier: 2 projects, 500MB DB, 5GB bandwidth | docs |
| TiDB Cloud API (Starter) | Lets an agent create and manage serverless MySQL-compatible TiDB clusters and run SQL, full-text and vector search queries against them. | API key | ✅ | 🆓 Free: up to 5 Starter instances per org, 25 GiB row storage + 25 GiB columnar storage + 250M Request Units per month in total; no credit card | docs |
| Tinybird API | Lets an agent ingest events into real-time ClickHouse-based data sources, run SQL queries and call published analytics API endpoints. | API key | ✅ | 🆓 Free plan: 10 GB storage, 1,000 API requests/day, 0.25 vCPU shared; no credit card | docs |
| Turso | Create and query edge SQLite (libSQL) databases programmatically via HTTP/SDK client libraries. | API key | ✅ | 🆓 Free tier: 100 databases, 5 GB storage, 500M rows read and 10M rows written per month, no card required | docs |
| Upstash (Redis, Vector) | Call serverless Redis, Vector, and QStash over HTTP REST API from edge/serverless runtimes. | API key | ✅ | 🆓 Free tier: Redis 256MB/500K cmds per month; Vector 10K queries+updates per day (max 200M vectors x dimensions, 1,536 dims) | docs |
Vector search, memory and RAG
Vector databases, retrieval (RAG) services and long-term memory layers for agents. — 9 services. JSON: catalog/databases-vector-memory.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Agentset RAG API | Lets an agent ingest documents into managed RAG namespaces and run semantic search or cited question answering over them. | API key | ✅ | 🆓 Free plan (forever): 1,000 pages ingested and 10,000 retrievals per month, 60 requests/min per namespace | docs |
| Chroma Cloud GitHub 599★ chroma-core/chroma-mcp | Create databases and store/query vector embeddings for retrieval via REST/SDK or MCP server. | API key | ✅ | Trial: Starter plan $0/month base with $5 one-time free credits on signup, then usage-based pricing | docs |
| Letta | Create and run stateful agents with persistent memory blocks via REST API or hosted MCP server. | API key | ✅ | 🆓 Free: $0/month plan with up to 3 stateful agents and limited Letta Auto usage (bring your own API keys); API plan $20/month + usage | docs |
| Mem0 | Add, search, update, and delete long-term agent memories via REST API or hosted MCP server. | API key | ✅ | 🆓 free (Hobby) tier: 10K add requests, 1K retrievals/mo, 1 project | docs |
| Pinecone GitHub 72★ pinecone-io/pinecone-mcp | Upsert, query, and rerank vector embeddings in managed indexes via REST/SDK or MCP server. | API key | ✅ | 🆓 free tier (Starter plan, limited pods/reads) | docs |
| Qdrant Cloud GitHub 1,537★ qdrant/mcp-server-qdrant | Create clusters and store/search vector embeddings via REST/gRPC API, SDKs, or official MCP server. | API key | ✅ | 🆓 Free tier: single-node cluster with 0.5 vCPU, 1 GB RAM, 4 GB disk, no card; suspends after 1 week idle | docs |
| Weaviate Cloud GitHub 163★ weaviate/mcp-server-weaviate | Store and semantically search vector objects in a managed cluster via REST/GraphQL or MCP server. | API key | ✅ | 🆓 Free: always-free plan, 1 cluster, 100,000 objects, 1 GB memory, 10 GB disk, 1 collection, no card required | docs |
| Zep | Store and retrieve temporal knowledge-graph agent memory via REST API or a single MCP endpoint. | API key | ✅ | 🆓 Free tier: 10,000 credits per month, no rollover; variable rate limits | docs |
| Zilliz Cloud (Milvus) GitHub 34★ zilliztech/zilliz-mcp-server | Manage Milvus clusters and perform vector search/ingestion via REST API, SDKs, or MCP server. | API key | ✅ | 🆓 Free tier: serverless cluster, 5GB storage, 2.5M vCUs per month, up to 5 collections, no card; plus up to $200 one-time trial credits ($100 on signup + $100 on adding a card) | docs |
Email, team chat and notifications
Send and receive email, post to team chat (Slack, Discord), send push notifications; manage meetings. — 10 services. JSON: catalog/communication-email-chat.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| AgentMail | Programmatically create inboxes and send/receive email autonomously, purpose-built for AI agents. | API key | ✅ | 🆓 Free: 3 inboxes, 3,000 emails/month (max 100/day), 3GB storage, no card required | docs |
| Discord API GitHub 507★ SaseQ/discord-mcp Smithery 82 uses | Send messages, manage channels/roles, and build interactive bots via REST and Gateway API. | API key / OAuth | ◐ | 🆓 free, no key needed beyond creating a bot application | docs |
| Mailgun SourceForge 1.0★/1 review | Send and validate transactional email via REST API and SMTP relay with webhooks. | API key | ✅ | 🆓 free: 100 emails/day; 30-day free trial on paid tiers | docs |
| ntfy.sh Push Notifications API | Lets an agent send push notifications to a user's phone or desktop by publishing a plain HTTP POST to an ntfy topic, and read messages back from it. | none | ◐ | 🆓 No key; anonymous publishing to public topics, rate-limited per visitor IP (burst of 60 requests, then 1 request every 5 s, roughly 17,280/day); paid plans from $6/month add reserved topics, higher limits, email and phone-call notifications. | docs |
| Postmark | Send transactional email via REST API with delivery tracking, bounce handling, and templates. | API key | ✅ | 🆓 free: 100 emails/month (Developer plan, no expiry) | docs |
| Resend SourceForge 4.0★/1 review | Send transactional and marketing email via REST API with templates, domains, and webhooks. | API key | ✅ | 🆓 free tier: 3,000 emails/mo, 100/day | docs |
| SendGrid (Twilio) SourceForge 3.9★/8 reviews | Send transactional and marketing email via REST/SMTP API with templates and analytics. | API key | — | Trial: 100 emails/day for 60 days, no card required; paid plan after | docs |
| Slack API Smithery 12.1k uses SourceForge 4.6★/250 reviews | Post messages, manage channels, and read conversation history in Slack via the Web API. | OAuth 2.0 | ✅ | 🆓 free, no key needed beyond creating a Slack app/workspace | docs |
| Stream (GetStream) Chat & Video API | Build and moderate in-app chat and video with REST/SDK APIs, channels, and real-time messaging. | API key | — | 🆓 Free tier: Build plan with 1,000 MAU/month and 100 concurrent connections, no card; Maker account gives $100/month credit for teams under 5 people and under $10k monthly revenue | docs |
| Zoom API | Schedule, update, and manage meetings, webinars, and cloud recordings programmatically via REST API. | OAuth 2.0 | ✅ | 🆓 usable on free Zoom account within Basic plan limits; some endpoints require paid plan | docs |
SMS and messaging apps
Send and receive SMS and messages on WhatsApp, LINE or Telegram through a messaging provider's API. — 10 services. JSON: catalog/sms-messaging.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| AWS End User Messaging SMS | Send SMS, MMS and voice messages and manage sender numbers, opt-outs and registrations via the AWS SMS and Voice v2 API. | cloud IAM | ✅ | Paid only; US SMS $0.00774/message + $0.00421 carrier fee (10DLC or toll-free) | docs |
| Bird (formerly MessageBird) | Send SMS, email and WhatsApp messages, verify phone numbers and track delivery via REST API or hosted MCP. | API key / OAuth | ✅ | Paid only; prepaid wallet, US long code or toll-free $0.0035/SMS + carrier fees | docs |
| LINE Messaging API | Lets an agent send and reply to messages, rich messages and broadcasts to users of a LINE Official Account and read user profiles. | API key | ✅ | 🆓 Free Communication plan (Japan): 200 push/broadcast messages/month; reply messages are unlimited. Beyond that only paid plans (Light JPY 5,000 for 5,000 messages, Standard JPY 15,000 for 30,000). Free quotas vary by region | docs |
| Plivo | Send and receive SMS and MMS worldwide and check delivery status via REST API. | API key | ✅ | Trial: $10 free credits, no card; then paid per message (US long code $0.0077/SMS + carrier surcharge) | docs |
| Sinch | Send and receive SMS (and WhatsApp, RCS and other channels) via the Conversation REST API. | API key | ✅ | Trial: free trial credit and a free test number on signup, no card; then paid (US 10DLC $0.0078/SMS + carrier fees) | docs |
| Telegram Bot API GitHub 1,692★ chigwell/telegram-mcp | Send/receive messages, media, and inline interactions via a simple HTTPS bot API. | API key | ◐ | 🆓 free, no key needed beyond a bot token from @BotFather | docs |
| Telnyx | Send and receive SMS, MMS, RCS and WhatsApp messages and manage phone numbers via REST API. | API key | ✅ | Trial: free testing credits on signup (amount not published); then paid (US 10DLC $0.004/SMS part + carrier fees) | docs |
| Twilio GitHub 111★ twilio-labs/mcp SourceForge 4.8★/13 reviews | Send/receive SMS, WhatsApp messages, and voice calls programmatically via REST API. | API key | ✅ | Trial: 100 SMS, 100 WhatsApp, 3,000 emails, 75 voice minutes; no card; one-time on signup, expires after 30 days | docs |
| Vonage API | Send SMS, make voice calls, and build video apps via a unified communications REST API. | API key | ✅ | trial/test credit on signup, then pay-as-you-go | docs |
| WhatsApp Business Cloud API GitHub 6,310★ lharries/whatsapp-mcp | Send/receive WhatsApp messages, template messages, and media programmatically via Graph API. | OAuth 2.0 | ◐ | 🆓 Free: non-template (service) messages inside an open 24h customer service window; template messages billed per message (per-message pricing since 2025-07-01) | docs |
Voice agents and telephony
Place and receive phone calls handled by AI voice agents, real-time audio/video rooms. — 8 services. JSON: catalog/voice-agents-telephony.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Bland AI | Programmatically create AI phone agents and place/manage automated outbound and inbound calls. | API key | ✅ | 🆓 free credits + inbound number on signup (Start plan), no credit card required | docs |
| Deepgram Voice Agent API | Run a full-duplex speech-to-speech voice agent pipeline (STT+LLM+TTS) over a WebSocket API. | API key | ✅ | $200 free credit on signup | docs |
| ElevenLabs Agents Platform | Build and deploy conversational AI voice agents with telephony (SIP/Twilio) integration via API and SDKs. | API key | ✅ | 🆓 Free plan: 10k credits/month shared across ElevenLabs products; no commercial license (from Starter, $6/month) | docs |
| LiveKit Cloud | Build and deploy real-time voice AI agents with SIP telephony support using LiveKit's server SDKs and APIs. | API key | — | 🆓 free Build plan: 1,000 agent session minutes/mo, 5,000 WebRTC participant minutes/mo, 50GB data transfer | docs |
| Retell AI SourceForge 1.0★/1 review | Build, deploy, and manage AI voice agents that handle phone and web calls via REST API and SDKs. | API key | ✅ | $10 free credit on signup, then pay-as-you-go ($0.07-$0.31/min for voice) | docs |
| Synthflow API SourceForge 1.0★/1 review | Create and manage AI phone voice agents and trigger/manage outbound calls programmatically via REST API. | API key | ✅ | Paid only: pricing page lists Enterprise contracts from $30,000/year; no self-serve free trial shown | docs |
| Twilio Programmable Voice GitHub 169★ twilio/twilio-oai GitHub 111★ twilio-labs/mcp | Programmatically make, receive, and control phone calls (IVR, recording, conferencing) via REST API. | API key | ✅ | Trial: one-time free units (e.g. 75 voice minutes, 100 SMS, 100 WhatsApp, 3,000 emails), no card, expires after 30 days; then pay-as-you-go | docs |
| Vapi | Create, configure, and run AI voice assistants that make and receive phone calls via REST API. | API key | ✅ | $5 free credit on signup, then pay-as-you-go (~$0.05/min platform fee + provider costs) | docs |
Productivity and workspace
Email, calendars, files, notes, tasks and project management. — 17 services. JSON: catalog/productivity-workspace.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Airtable API GitHub 457★ domdomegg/airtable-mcp-server Smithery 500 uses SourceForge 4.7★/28 reviews | Read and write records in Airtable bases and tables via REST API. | API key / OAuth | ✅ | 🆓 Free tier: 1,000 API calls per workspace per month on the Free plan, 5 req/sec per base | docs |
| Asana API Smithery 94 uses SourceForge 4.7★/97 reviews | Create tasks, projects, and comments in Asana workspaces via REST API. | API key / OAuth | ✅ | 🆓 free tier: API included on Personal (free) plan, rate limited | docs |
| Atlassian (Jira, Confluence) | Create and manage Jira issues and Confluence pages via REST API or the official remote MCP server. | OAuth 2.0 | ✅ | 🆓 free tier: available on Free Jira/Confluence plans; rate limits vary by plan | docs |
| Box API | Upload, download, and manage files, folders, and metadata in Box via REST API. | OAuth 2.0 | ✅ | 🆓 Free: developer plan with 10 GB storage, full API access and 1,000 AI units per month, no payment required | docs |
| Cal.com API | Create and manage bookings, event types, and availability via the Cal.com REST API v2. | API key / OAuth | ✅ | 🆓 free tier: API included on Free plan, 120 req/min (higher limits on request) | docs |
| Calendly API Smithery 23 uses SourceForge 4.7★/14 reviews | Programmatically book meetings and read/write scheduling, event, and contact data via REST API v2. | API key / OAuth | ✅ | 🆓 Free: API reads and most writes work on every plan incl. Free (except 3 Enterprise-only endpoints); booking through the Scheduling API (POST /invitees) and webhooks need a paid plan | docs |
| ClickUp API SourceForge 4.6★/122 reviews | Create and manage ClickUp tasks, lists, and docs via REST API or the official MCP server. | API key / OAuth | ✅ | 🆓 free tier: API access included on Free Forever plan | docs |
| Coda API (Superhuman Docs) | Read and write Coda (now 'Superhuman Docs') documents, tables, and rows via REST API or an MCP server. | API key | ✅ | 🆓 free, included for all users on both free and paid workspaces | docs |
| Dropbox API SourceForge 4.5★/226 reviews | Upload, download, and manage files and folders in Dropbox via the HTTP REST API. | OAuth 2.0 | ✅ | 🆓 free tier: API access included on Basic (free) plan, rate limited | docs |
| Google Workspace APIs (Gmail, Calendar, Drive) | Read/write Gmail messages, Calendar events, and Drive files programmatically via REST APIs. | OAuth 2.0 | ✅ | 🆓 Free: no charge within per-API daily quotas; Google plans to bill quota overages to the Cloud billing account later in 2026 | docs |
| Linear API Smithery 3,816 uses SourceForge 5.0★/1 review | Create, query, and update Linear issues, projects, and comments via GraphQL API or the official MCP server. | API key / OAuth | ✅ | 🆓 free tier: API access included on Free plan (rate limited) | docs |
| Microsoft Graph (Outlook, Teams, OneDrive) | Single REST endpoint to read/write Outlook mail, Calendar events, Teams, and OneDrive/SharePoint data. | OAuth 2.0 | ✅ | 🆓 free with a Microsoft 365/Entra ID tenant (free dev tenant via Microsoft 365 Developer Program) | docs |
| monday.com API SourceForge 4.8★/98 reviews | Query and update monday.com boards, items, and workflows via GraphQL API or a hosted MCP endpoint. | API key / OAuth | ✅ | 🆓 free tier: GraphQL API included on Free plan (rate limited) | docs |
| NocoDB Cloud API | Lets an agent read, create and update records, tables and views in NocoDB spreadsheet-style databases. | API key / OAuth | ✅ | 🆓 Free plan: 1,000 records, 1 GB storage, 1,000 API calls/month, 3 editors, 100 automation runs; no credit card | docs |
| Notion API Smithery 3,841 uses SourceForge 4.7★/26 reviews | Read, create, and update Notion pages, databases, and comments via REST API. | API key / OAuth | ✅ | 🆓 free, API access included on all plans (rate limit ~3 req/sec) | docs |
| Todoist API SourceForge 4.8★/14 reviews | Create, read, and complete Todoist tasks and projects via REST API or the official MCP server. | API key / OAuth | ✅ | 🆓 free to use; some features gated by the user's Todoist plan | docs |
| Trello API | Create and manage Trello boards, lists, and cards via REST API. | API key / OAuth | ✅ | 🆓 free, no key needed to register an app; usage is rate limited | docs |
CRM, support and marketing
Contacts, deals, support tickets and email campaigns. — 8 services. JSON: catalog/crm-support-marketing.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Attio API Smithery 277 uses | Search, create, and update records, lists, and notes in an Attio CRM workspace via REST API or official MCP. | API key / OAuth | ✅ | 🆓 Free tier: up to 3 seats, 50,000 records, API access included; no card required; 14-day trial of Pro plan | docs |
| HubSpot API Smithery 1,166 uses | Create/update CRM contacts, deals, companies, and engagements, or send marketing emails, via REST API or remote MCP. | API key / OAuth | ✅ | 🆓 free CRM account with limited-scope API access; many endpoints require a paid Hub tier (see APIs-by-tier docs) | docs |
| Intercom API SourceForge 4.7★/9 reviews | Manage conversations, contacts, companies, and Help Center articles via REST API or Intercom's official remote MCP server. | API key / OAuth | ✅ | 🆓 free development workspace for building/testing; production use requires a paid Intercom plan | docs |
| Klaviyo API Smithery 2 uses SourceForge 4.5★/8 reviews | Manage email/SMS marketing profiles, lists, flows, and campaign analytics via Klaviyo's REST API or official MCP server. | API key / OAuth | ✅ | 🆓 free plan up to 250 contacts / 500 email sends per month | docs |
| Mailchimp Marketing API | Manage email marketing audiences, campaigns, and automation via Mailchimp's Marketing REST API. | API key / OAuth | ◐ | 🆓 free plan up to 250 contacts / 500 emails per month (API accessible on free plan) | docs |
| Pipedrive API SourceForge 4.4★/50 reviews | Create and update deals, contacts (persons/organizations), and activities in a Pipedrive CRM pipeline via REST API. | API key / OAuth | ✅ | no free tier; 14/30-day trial and free developer sandbox account for testing | docs |
| Salesforce APIs GitHub 479★ salesforcecli/mcp SourceForge 4.7★/60 reviews | Read and write Salesforce CRM records (leads, opportunities, cases) programmatically via REST, GraphQL, or Bulk API. | OAuth 2.0 | ✅ | 🆓 free Developer Edition org available via signup at developer.salesforce.com/signup | docs |
| Zendesk API GitHub 122★ reminia/zendesk-mcp-server SourceForge 4.3★/20 reviews | Create, update, and search support tickets, users, and Help Center articles via Zendesk's REST API. | API key / OAuth | ◐ | Trial: 14-day free trial of Suite Professional, one-time, no credit card required; no free plan, paid plans from $19/agent/mo (Support Team, annual) | docs |
Social media
Read and publish posts, comments and videos on social platforms. — 10 services. JSON: catalog/social-media.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Ayrshare SourceForge 3.4★/5 reviews | Unified API to post, schedule, and analyze content across 14+ social networks (X, Instagram, LinkedIn, TikTok, etc.) with one API key. | API key | ✅ | Trial: one-time 28-day free trial of the Launch plan ($299/mo), no card required; Premium from $149/mo | docs |
| Bluesky / AT Protocol | Post, read, and moderate content on Bluesky via the open, self-hostable AT Protocol REST/XRPC API. | OAuth 2.0 | — | 🆓 free, no key needed for public reads; free account required for posting | docs |
| LinkedIn API | Sign users in and share basic posts via OAuth2/OpenID Connect; most other endpoints require partner approval. | OAuth 2.0 | — | check pricing — most scopes require LinkedIn Partner Program approval | docs |
| Mastodon API SourceForge 2.5★/11 reviews | Post statuses, read timelines, and manage accounts on any Mastodon instance via REST API. | OAuth 2.0 | — | 🆓 free, no central key; register an app per instance, no cost | docs |
| Meta Graph API (Facebook, Instagram) | Read and publish posts, manage Pages, and access Instagram business content via Meta's Graph API. | OAuth 2.0 | ✅ | 🆓 free, but most non-trivial read/write permissions require Meta App Review and business verification | docs |
| Pinterest API SourceForge 4.7★/14 reviews | Create pins and boards and read analytics data on Pinterest via REST API v5. | OAuth 2.0 | — | 🆓 free tier: standard rate limits; higher limits/trial access require app review | docs |
| Reddit API SourceForge 4.2★/8 reviews | Read posts/comments and submit posts, comments, or votes on Reddit via OAuth2 REST API. | OAuth 2.0 | — | 🆓 free for non-commercial/personal use under Reddit Data API terms; commercial or high-volume use requires a paid Data API license | docs |
| TikTok API SourceForge 4.7★/6 reviews | Post videos/drafts and query content on TikTok via the Content Posting and Display OAuth2 REST APIs. | OAuth 2.0 | — | 🆓 Free: no fee; requires app review for production access, sandbox mode for testing; posts from unaudited clients are private-only until the app passes TikTok's audit | docs |
| X (Twitter) API | Post, search, and read tweets and manage X (Twitter) content via REST API v2. | API key / OAuth | ✅ | Paid only: pay-per-usage with prepaid credits (e.g. $0.005 per Post read, $0.001 per owned read), no subscriptions and no free tier | docs |
| YouTube Data API | Search videos, manage playlists/comments, and upload videos to YouTube via REST API. | API key / OAuth | — | 🆓 Free tier: 10,000 quota units/day plus separate caps of 100 search.list and 100 videos.insert calls/day (extendable on request) | docs |
Maps, geolocation and weather
Geocoding, routing, places, map tiles and weather forecasts. — 16 services. JSON: catalog/maps-geo-weather.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Esri ArcGIS Location Platform | Geocode addresses, render maps, run spatial analysis and manage geospatial site data via REST APIs and SDKs. | API key / OAuth | ✅ | 🆓 free tier with monthly free credits, then usage-based pricing | docs |
| Geoapify | Geocode, search places, and calculate routes/isochrones via REST APIs built on open geodata. | API key | ✅ | 🆓 free tier: 3,000 credits/day (~90,000/month), no card required | docs |
| Google Maps Platform SourceForge 4.7★/6 reviews | Geocode addresses, get directions/routes, places data, and static/dynamic maps via REST APIs or Google's remote MCP server. | API key | ✅ | 🆓 Free tier: free calls per SKU per month (10K Essentials, 5K Pro, 1K Enterprise), replacing the former $200 monthly credit | docs |
| HERE Location Services | Geocode, route, and search places worldwide via REST APIs and SDKs. | API key | ◐ | 🆓 free tier: roughly 30,000 transactions/month on the Base/Freemium plan | docs |
| IP2Location.io API | Lets an agent geolocate IPv4/IPv6 addresses, get ASN/ISP/proxy data, and look up domain WHOIS records. | API key | ✅ | 🆓 Free plan: 50,000 IP geolocation queries/month, 500 domain WHOIS and 50 hosted-domain queries/month (attribution required); keyless: 1,000 queries/day. | docs |
| IPLocate IP Intelligence API | Lets an agent geolocate an IP address and get its ASN, ISP, company, abuse contacts and VPN/proxy/Tor/hosting flags. | API key | ✅ | 🆓 Free plan: 1,000 requests/day forever, all data types (geolocation, VPN/proxy/Tor, ASN, company, abuse contacts), no credit card. | docs |
| LocationIQ | Geocode and reverse-geocode addresses, find nearby places, look up time zones, calculate routes and render map tiles via REST API. | API key | — | 🆓 Free: 5,000 requests/day, 2 requests/s, 60 requests/min, no card; commercial use requires a link back to LocationIQ | docs |
| Mapbox GitHub 356★ mapbox/mcp-server | Geocode, route, and render maps/POI search via REST APIs, SDKs, or an official MCP server. | API key | ✅ | 🆓 free tier: monthly free quotas per API (e.g. 50,000 map loads/month) | docs |
| National Weather Service API (NWS) | Fetch official US government weather forecasts, alerts, and observations via a free public REST API. | none | ◐ | 🆓 free, no key, no rate-limit tier (fair-use) | docs |
| Open-Meteo | Fetch weather forecasts, historical weather, and climate data worldwide via a free open REST API, no key required. | none | ◐ | 🆓 No key needed for non-commercial use: 10,000 calls/day, 300,000/month (also 600/min, 5,000/hour) | docs |
| OpenCage Geocoding API | Convert addresses and place names to coordinates, and coordinates to addresses, worldwide via REST API. | API key | ✅ | 🆓 Free: 2,500 requests/day, 1 request/s, no card (for testing; production needs a paid plan from €45/month) | docs |
| OpenRouteService | Calculate routes, isochrones, distance matrices, and geocoding over OpenStreetMap data via a free REST API. | API key | ◐ | 🆓 free tier: ~2,000 requests/day (varies by endpoint), signup required | docs |
| OpenStreetMap Nominatim | Geocode and reverse-geocode addresses from OpenStreetMap data via a free public REST API. | none | ◐ | 🆓 No key needed; public server max 1 request/second, bulk geocoding discouraged (small one-off jobs only, cached), no systematic or autocomplete queries | docs |
| OpenWeatherMap API GitHub 5★ robertn702/mcp-openweathermap | Fetch current weather, forecasts, and historical/air-quality data for any location via a REST API. | API key | ✅ | 🆓 Free tier: 60 calls/min, 1,000,000 calls/month on current weather/forecast | docs |
| Overpass API (OSM) | Run custom queries (Overpass QL) over OpenStreetMap data - POIs, roads, boundaries - via a public read-only API. | none | ◐ | 🆓 free, no key; public instances are fair-use/rate-limited | docs |
| Tomorrow.io API | Get hyperlocal weather forecasts, historical data, and alerts for any coordinates via REST API or an official MCP server. | API key | ✅ | 🆓 free tier: 500 requests/day, 3 req/sec, 1 monitored location/alert | docs |
Finance, payments and market data
Accept payments, move money, access bank data and query stock, FX and crypto prices. — 16 services. JSON: catalog/finance-payments.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Adyen API GitHub 79★ Adyen/adyen-openapi SourceForge 4.0★/1 review | Process payments, payouts, and manage disputes/balances across global payment methods via REST API. | API key | ✅ | paid only; requires a signed merchant contract, pay per-transaction | docs |
| Alpaca Trading API | Place stock/options/crypto trades and stream market data via REST/WebSocket API, with free paper trading. | API key | ✅ | 🆓 free paper trading (unlimited); free basic (IEX) market data feed | docs |
| Alpha Vantage | Fetch stock, forex, crypto prices and technical/fundamental indicators via a free REST API. | API key | ✅ | 🆓 free tier: 25 requests/day | docs |
| Coinbase (CDP / x402) SourceForge 4.4★/10 reviews | Create wallets, send crypto, and pay per-API-call with stablecoins over HTTP (x402) via the Coinbase Developer Platform SDK. | API key | ✅ | 🆓 Free tier: CDP x402 Facilitator free for 1,000 onchain transactions/month, then $0.001/tx; payment verification always free | docs |
| CoinGecko API SourceForge 5.0★/1 review | Fetch live and historical crypto prices, market data, and NFT data via REST API or the official CoinGecko MCP server. | API key | ✅ | 🆓 Free tier: Demo API plan 10,000 calls/month, 100 calls/min, attribution required; keyless free MCP with shared rate limits | docs |
| CoinMarketCap API | Lets an agent fetch live and historical cryptocurrency prices, market caps, listings, exchange and DEX data, and indices like Fear & Greed. | API key | ✅ | 🆓 Free Basic plan: 15,000 credits/month, 50 requests/min, 1 API key, commercial use allowed; plus a keyless public API with lower rate limits | docs |
| DexPaprika DEX API | Lets an agent query on-chain DEX data across 36 blockchains: liquidity pools, swaps, token prices, OHLCV history and live price streams. | none | ✅ | 🆓 No key; 30,000 credits per rolling 30 days per IP at 15 requests/min. Free registered key: 100,000 credits/30 days at 30 requests/min, no card | docs |
| Financial Modeling Prep SourceForge 3.6★/13 reviews | Fetch company financials, stock prices, and fundamental data via a REST API. | API key | ✅ | 🆓 free tier: 250 requests/day (limited endpoints) | docs |
| Mercado Pago API | Lets an agent create checkout preferences, payments, refunds and subscriptions and look up transactions in Latin America's Mercado Pago. | API key / OAuth | ✅ | 🆓 Free to integrate: no API or monthly fees, only per-transaction commissions; free test credentials and test users for sandbox payments | docs |
| Open Exchange Rates | Fetch current and historical foreign-exchange rates for 200+ currencies via a REST API. | API key | — | 🆓 free tier: 1,000 requests/month, USD base only, hourly updates | docs |
| PayPal API SourceForge 4.3★/22 reviews | Process payments, payouts, invoices, and subscriptions via REST API or PayPal's official MCP server. | API key / OAuth | ✅ | 🆓 free to integrate; pay per-transaction fees only; sandbox for testing | docs |
| Plaid API GitHub 118★ plaid/plaid-openapi SourceForge 4.4★/5 reviews | Link bank accounts and fetch balances, transactions, and identity data via REST API/SDKs. | API key | ✅ | Trial: Sandbox always free; new US/Canada teams (since 2026-04-15) get a free Trial plan with up to 10 Production Items one-time; then pay-as-you-go | docs |
| Polygon.io / Massive | Query real-time and historical stocks, options, forex, and crypto market data via REST/WebSocket API. | API key | ✅ | 🆓 free tier available (delayed data, limited calls/min); paid plans for real-time | docs |
| Square API GitHub 76★ square/connect-api-specification | Process in-person/online payments, manage orders, invoices, and catalog via REST API and SDKs. | API key / OAuth | ✅ | 🆓 free to integrate; pay per-transaction processing fees; free Sandbox for testing | docs |
| Stripe API Smithery 48 uses SourceForge 4.1★/17 reviews | Create payments, subscriptions, invoices, and refunds programmatically via REST API or the official Stripe MCP server. | API key / OAuth | ✅ | 🆓 free to integrate; pay per-transaction fees only, no monthly fee | docs |
| Wise API | Send international transfers, check exchange rates, and manage multi-currency balances via REST API. | API key / OAuth | ◐ | 🆓 free API access; normal Wise transfer fees apply per transaction; sandbox available | docs |
E-commerce
Manage stores, products, orders and marketplace listings. — 8 services. JSON: catalog/ecommerce.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Amazon Selling Partner API GitHub 912★ amzn/selling-partner-api-models | Manage listings, orders, inventory, and reports for an Amazon seller/vendor account via REST API. | OAuth 2.0 | ✅ | 🆓 free API access; requires an existing Amazon Seller/Vendor Central account | docs |
| BigCommerce API SourceForge 5.0★/1 review | Manage catalog, orders, customers, and carts on a BigCommerce store via REST/GraphQL APIs. | API key / OAuth | ✅ | 🆓 free API access; requires an active BigCommerce store plan | docs |
| eBay APIs SourceForge 4.0★/10 reviews | List items, manage orders/inventory, and search listings across eBay marketplaces via REST APIs. | OAuth 2.0 | ✅ | 🆓 free developer tier with call-volume limits; sandbox environment included | docs |
| Etsy Open API v3 | List products, manage orders/shop, and search listings on the Etsy marketplace via REST API. | OAuth 2.0 | ✅ | 🆓 Free: developer keystring at no cost; rate limits (QPS/QPD) are set per app and shown in the Developer Portal | docs |
| Mercado Libre API | Lets an agent search items and categories and manage a seller's listings, orders, questions, shipments and promotions on the Mercado Libre marketplace. | OAuth 2.0 | — | 🆓 Free API access for any Mercado Libre account that creates an app in DevCenter; only normal marketplace selling fees apply | docs |
| Printful API SourceForge 3.0★/3 reviews | Create print-on-demand products, sync catalogs, and submit fulfillment orders via REST API. | API key / OAuth | — | 🆓 free API access; pay only for products/fulfillment/shipping ordered | docs |
| Shopify Admin / Storefront API | Manage products, orders, customers, and inventory (Admin API) or build storefronts (Storefront API) via REST/GraphQL. | API key / OAuth | ✅ | 🆓 free API access; requires an active paid Shopify store subscription to use | docs |
| WooCommerce REST API | Manage products, orders, and customers on a self-hosted WooCommerce store via REST API. | API key | ✅ | 🆓 free (self-hosted plugin; no vendor API fees, only your own WordPress hosting costs) | docs |
Automation and integration platforms
One connection that exposes thousands of third-party app actions to an agent, with managed auth. — 15 services. JSON: catalog/automation-integration.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Activepieces | Build, run and manage no-code flows across 400+ apps via REST API or the built-in MCP server. | API key | ✅ | 🆓 free: open-source, self-hostable at no cost; cloud free plan gives 100 credits/day, no card required | docs |
| Arcade.dev | Execute authorized tool calls (GitHub, Slack, Google, etc.) with managed OAuth via API, SDK, or 200+ MCP servers. | API key / OAuth | ✅ | 🆓 free tier: 2,000 auth events + 2,000 tool calls/mo, no credit card required | docs |
| Composio | Discover, authorize and execute actions across 1,500+ SaaS toolkits through a unified API, SDK, or MCP session. | API key / OAuth | ✅ | 🆓 free tier: 100,000 tool calls + 50,000 trigger events/mo, no credit card required | docs |
| Gumloop | Create AI agents, start chat sessions, and trigger no-code automations via REST API, SDKs, or the Gumloop MCP server. | API key / OAuth | ✅ | 14-day free trial of Pro (20,000 credits), requires credit card, no permanent free tier | docs |
| IFTTT API SourceForge 5.0★/4 reviews | Fire a webhook event to trigger pre-configured Applets that act in connected consumer apps (Pro plan required). | API key | ✅ | no free-plan access; Webhooks/API require Pro plan ($2.99+/mo) | docs |
| Keboola Storage API | Lets an agent load and query tables, create SQL and Python transformations, and trigger data pipeline jobs in a Keboola project. | API key / OAuth | ✅ | 🆓 Free plan: 1 project, 120 compute minutes in the first month then 60 minutes/month, extra-small Snowflake backend; no credit card | docs |
| Make API / MCP | Trigger and manage Make automation scenarios, or call MCP tools, via REST API and a native MCP server/client. | API key | ✅ | 🆓 Free tier: 1,000 credits/month, 2 active scenarios; Make API access requires Core plan or higher | docs |
| Merge (Agent Handler) | Give an agent governed, audited tool access to Salesforce, Slack, Jira and 100+ enterprise apps via API or MCP. | API key | ✅ | 🆓 Free tier: 2,000 credits/month for prototyping/testing; production usage needs a paid Pro ($1,000/mo, 25,000 credits) or Enterprise plan | docs |
| n8n API SourceForge 5.0★/1 review | Create, run and monitor n8n workflows via REST API, and expose or consume tools through MCP trigger/client nodes. | API key | ✅ | 🆓 Free: self-hosted Community Edition (open source, unlimited); n8n Cloud trial has no API access | docs |
| Nango | Authorize end users to 400+ third-party APIs/MCP servers and proxy authenticated calls to them from your app or agent. | API key / OAuth | ✅ | 🆓 free tier: 10 connections, 10 compute hours, 10GB data transfer/mo | docs |
| Paragon ActionKit | Call thousands of pre-built Tools and Triggers across 130+ SaaS apps (Slack, Salesforce, Gmail) via API or MCP. | API key / OAuth | ✅ | Trial: free trial only; no lasting free tier confirmed; Pro/Enterprise pricing by quote | docs |
| Pipedream Connect | Call 2,700+ app APIs and run managed-auth actions on end users' behalf via REST API or Pipedream MCP servers. | API key / OAuth | ✅ | 🆓 Free tier: free workspaces get a daily credit limit and limited connected accounts; Connect is free in development mode, production use needs a paid plan | docs |
| StackOne | Call 520+ SaaS connectors (HRIS, ATS, CRM, documents) through one unified API or MCP gateway covering 32,000+ actions. | API key | ✅ | 🆓 free tier: 1,000 action-call credits/seat/mo (Starter), no credit card required | docs |
| Superglue | Connect and orchestrate enterprise systems (ERP, CRM, databases) through a self-serve API and per-integration MCP servers. | API key | ✅ | 🆓 free tier: Pro plan free to start, 3,000 executions/mo and 5M tokens/mo included, self-serve signup | docs |
| Zapier MCP / AI Actions | Call 9,000+ apps and 40,000+ pre-built actions (Slack, Gmail, Sheets, etc.) through one MCP endpoint. | API key / OAuth | ✅ | 🆓 Free tier: 100 tasks/month; each successful MCP tool call uses 2 tasks (~50 calls/month); more on paid plans | docs |
Model APIs and inference
LLM, embedding and multimodal model endpoints an agent can delegate sub-tasks to. — 18 services. JSON: catalog/model-inference.json · details page
| Service | What an agent can do | Auth | MCP | Free tier | Docs |
|---|---|---|---|---|---|
| Anthropic Claude API | Send messages to Claude models for text and vision generation, tool use, batch jobs and document analysis. | API key | — | paid only | docs |
| Cohere API SourceForge 4.0★/1 review | Call chat, embed, rerank and classify endpoints for text generation, semantic search and RAG. | API key | — | 🆓 free trial key: 1,000 calls/mo, rate-limited | docs |
| Comet Opik Cloud API | Lets an agent log and read LLM traces and spans, score them with evaluations and manage datasets and prompts in Opik. | API key / OAuth | ✅ | 🆓 Free cloud plan: 25k spans/month, 60-day data retention, up to 10 team members | docs |
| DeepSeek API SourceForge 5.0★/1 review | Send chat and reasoning requests to DeepSeek models via an OpenAI- and Anthropic-compatible REST API. | API key | — | paid only | docs |
| fal.ai | Generate images, video, audio and 3D with 1,000+ hosted models via queued REST or real-time WebSocket. | API key / OAuth | ✅ | Paid only; prepaid credits, priced per model (e.g. FLUX.1 schnell $0.003/megapixel) | docs |
| Fireworks AI | Run serverless or dedicated inference and fine-tuning for open models via OpenAI-compatible APIs. | API key | — | trial credits: $1 on signup | docs |
| Google Gemini API | Generate text and images, analyze multimodal input (video, audio, PDFs), and run code execution with Gemini models. | API key | — | 🆓 free tier: rate-limited access to Flash/Pro models | docs |
| Groq API | Run fast LLM chat, tool use and speech-to-text on hosted open models via an OpenAI-compatible API. | API key | — | 🆓 free tier: rate-limited per model, no card | docs |
| Hugging Face Inference Providers | Call hundreds of open-weight chat, vision, image, video and audio models across many providers with one HF token. | API key | ✅ | 🆓 Free tier: $0.10/month in Inference Providers credits (PRO $2.00/month) | docs |
| Mistral AI API SourceForge 5.0★/1 review | Run chat completions, embeddings, OCR and document processing with Mistral models via REST. | API key | ✅ | 🆓 free tier: Studio free mode, rate-limited | docs |
| OpenAI API SourceForge 5.0★/3 reviews | Generate text, images, audio and embeddings, and run tool-calling via the Responses and Chat Completions APIs. | API key | ✅ | paid only | docs |
| OpenRouter SourceForge 5.0★/1 review | Route chat requests to hundreds of LLMs from many providers through one OpenAI-compatible endpoint with fallback. | API key / OAuth | ✅ | 🆓 free models: 50 req/day (1,000/day after $10 purchase) | docs |
| PiAPI GitHub 75★ apinetwork/piapi-mcp-server | Generate images, video and music through one API proxying Midjourney, Flux, Kling and other models. | API key | ◐ | trial credits: $0.50 on signup | docs |
| Replicate | Run thousands of hosted image, video, audio and text models via HTTP predictions; also fine-tune and deploy. | API key | ✅ | paid only | docs |
| Together AI | Run serverless inference, batch jobs, fine-tuning and dedicated GPU endpoints for open-source models. | API key | — | Paid only: no free trial; minimum $5 prepaid credit purchase | docs |
| Vercel AI Gateway | Send chat, image, embedding and rerank requests to 100+ models through one gateway with failover and spend tracking. | API key / OAuth | — | 🆓 free tier: monthly credits on subset of models | docs |
| Voyage AI (embeddings/rerank) | Generate text, code and multimodal embeddings and rerank documents for RAG and semantic search. | API key | — | 🆓 free tier: 200M tokens on current models | docs |
| xAI Grok API | Generate text, images, video and voice with Grok models, with built-in web search and code tools. | API key | — | paid only (prepaid credits) | docs |
Related directories and registries
Other machine-readable sources agents can use to discover tools:
- Official MCP Registry — The official Model Context Protocol registry; agents can call its REST API (with OpenAPI spec) to search and list available MCP servers. — JSON/API
- public-apis/public-apis — A community-curated GitHub list of 1,400+ free public APIs by category, fetchable as raw Markdown for programmatic parsing. — JSON/API
- APIs.guru OpenAPI Directory — An open, unauthenticated directory of 2,500+ public OpenAPI specs; agents fetch list.json to discover APIs and their OpenAPI definitions. — JSON/API
- punkpeye/awesome-mcp-servers — A widely-starred curated GitHub list of MCP servers by category, fetchable as raw Markdown for automated discovery. — JSON/API
- Smithery — An MCP server registry and hosting gateway (6,000+ servers) whose REST API lets agents search servers and obtain connection URLs. — JSON/API
- Glama MCP Directory — A large scanned and scored registry of 90,000+ open-source MCP servers, queryable via a bearer-authenticated REST API. — JSON/API
- mcp.so — A community MCP server marketplace and browsable directory site, but it has no publicly documented JSON/REST API for programmatic access.
- PulseMCP — A directory of 21,800+ MCP servers updated daily; its Sub-Registry REST API (API key required) lets agents list and search servers. — JSON/API
- llms.txt convention / directory — An open convention for a root-level llms.txt file giving agents a concise Markdown map of a site's key content; a community directory indexes published files, though it exposes no JSON API. — JSON/API
- Postman API Network — The largest network of public API collections shared on Postman, browsable on the web but with no documented public API for programmatic discovery.
- RapidAPI Hub (Nokia API Hub) — A large third-party API marketplace with growing MCP support for agents, but with no public, unauthenticated catalog endpoint for bulk discovery.
Contributing
Edit only the files in data/ (usually data/catalog.json), run python scripts/build.py to regenerate the English, Polish and LLM files, and open a pull request. Every new entry must link to the vendor's official API documentation. Step-by-step guide: CONTRIBUTING.md.
See also
References
The initial candidate list was compiled from: